1. Field of the Invention
The present invention relates to a parking assist system that assists a vehicle in parking by automatic steering using an electric power steering unit.
2. Description of Related Art
A parking assist system is known which assists a vehicle in parking by automatic steering using an electric power steering unit. Japanese Unexamined Patent Application Publication No. 2003-341543 (JP 2003-341543 A) describes a parking assist system that automatically performs a steering operation. In the parking assist system, stationary steering of performing a steering operation in a state where a vehicle stops is carried out.
When the stationary steering is carried out as described above in a state where the temperature of the electric power steering unit is high, the temperature of the electric power steering unit further rises due to generation of heat and there is a possibility that the electric power steering unit will lose functionality. Japanese Unexamined Patent Application Publication No. 2010-228591 (JP 2010-228591 A) describes a parking assist controller that includes a temperature sensor measuring the temperature of a motor of an electric power steering unit and an ambient temperature sensor measuring the ambient temperature of the electric power steering unit. When the temperature of the motor measured by the temperature sensor departs from a predetermined temperature range or the ambient temperature of the electric power steering unit measured by the ambient temperature sensor departs from a predetermined temperature range, the parking assist controller stops parking assist.
However, when the parking assist using the electric power steering unit is stopped, the vehicle has to be parked by the driver's steering operation.